The present teachings are predicated upon providing a system and method for producing a low cost coated paperboard with desirable optical properties that substantially retains its optical properties such as brightness when the coating is wetted. Generally, paperboard may include one or more brown layers. The brown layers may be covered by one or more lighter layers such as a white fiber layer and the lighter layers may be covered by one or more coating layers. Currently the cost of purchasing the white fiber is increasing and there is increasing pressure to lower the cost of the coated paperboard. One way to lower the cost of the paperboard is by removing the white fiber layer. Attempts have been made to remove the white fiber layer from the coated paperboard; however, when the white fiber layer is not applied between the brown layer and the coating layer, the brown layer may be visible through the coating layer, the brown layer may become visible through the coating layer when water is applied to the coating layer, or both. Visibility of the brown layers through the coating layers deteriorates the optical properties and causes the coated paperboard to be rejected or sold at a reduced price.
Examples of devices, methods, and/or compositions used to coat paperboard may be found in U.S. Pat. Nos. 5,837,762; 6,982,003; 7,101,592; 7,169,445; 7,425,246; 7,473,333 and International Patent Application Nos. WO2009/042371 and WO2010/042162 all of which are incorporated by reference herein for all purposes. In one example, U.S. Pat. No. 7,425,246 discusses a concept where desired properties are achieved by coating board with a combination of an interface (i.e., under) and internal (i.e., over) layers of similar coat weight. The present teachings seek to solve these problems by proving a system and method for producing a coated paperboard with desirable optical properties that has reduced amounts and/or is free of a bright fiber layer or a white fiber layer and retains its optical properties when water is applied to the coating. It would be attractive to have an improved coated paperboard that retains its optical properties when water is applied to the coating. It would be attractive to have a system and method for applying an opaque layer and a barrier layer simultaneously so that the opaque layer is protected by the barrier layer and the paperboard retains its desirable optical properties and an improved coating is provided on the paperboard.